Forecast model description
  Climate Seasonal Forecasts Forecast model description

Model designation

SL-AV

Resolution

Horizontal

Horizontal – 1.125/1.40625 degrees lat/lon

Vertical     -  28 levels

Vertical

28 sigma-levels

Physics

Moist processes

The precipitation is produced by the large-scale and deep convective condensation processes under supersaturation conditions. Large-scale precipitation calculation is based on the diagnostically defined water content under the Marshal – Palmer drop size distribution function and prescribed drops concentration. The drop falling velocity is calculated in dependence of it’s diameter. Subsequent evaporation of large-scale precipitation in nonsaturated lower layer follows modified parameterization of Kessler (1969).

Radiation

The radiation fluxes calculation method is based on delta – Eddington two-stream approximation to transfer equation solution for short wave and long wave parts of spectra (Geleyn, Hollingsworth, 1979; Ritter, Geleyn, 1992). Cloud geometry is with two possible options: random and maximum overlap.

Planetary boundary layer

The vertical turbulent transport of moment, heat and moisture in the surface layer is described using Monin – Obukhov theory for different stratification type. Above, in PBL the K – theory is used. The modified Richardson number is applied in this procedure.

Land-surface

The surface processes include a simple moister and mass exchange parametrizations

Sea Surface Temperature (SST) specification: persisted initial SST anomalies.

Ensemble size - 10 members.

 
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